The present invention relates to water-in-oil emulsion prespotter laundry compositions. More particularly, the invention relates to water-in-oil emulsion prespotter laundry compositions containing enzymes and specific polyester or polyether polyols, which stabilize the enzymes to prevent their degradation during prolonged storage.
The use of detergent and laundry prespotter compositions containing enzymes is well known in the art. For detergent compositions containing enzymes, see, for example, U.S. Pat. Nos. 3,557,002; 3,634,258; 4,090,973; 4,238,345; and 4,272,396. For prespotter compositions containing enzymes, see, for example, U.S. Pat. Nos. 3,741,902 and 3,953,353.
Moreover, the art recognizes "that the formulation of enzyme-containing liquid detergent compositions is a very delicate task due to the rapid decrease of the enzymatic activity in aqueous medium during storage."(U.S. Pat. No. 4,111,855, col. 1, lines 39-42).
Numerous attempts have been made to provide aqueous enzyme-containing compositions, wherein the enzymatic activity is claimed to be preserved by the incorporation of stabilizing agents. For example, the following enzyme stabilizing agents are disclosed in the patent literature. U.S. Pat. No. 3,557,002 (a short chain alkyl monohydroxy alcohol or an alkoxy short chain monohydroxy alcohol, along with a nonionic or zwitterionic detergent): U.S. Pat. No. 3,607,653 (polyethylene glycol polymers); U.S. Pat. No. 3,627,688 (dialkyl glycol ethers, heterocylic ethers and dialkyl ketones, along with a nonionic or zwitterionic detergent); U.S. Pat. No. 3,682,842 (enzyme-ion binding agents such as trichloracetic acid, tungstic acid, phosphotungstic acid, tannic acid, sulfosalicyclic acid, and certain dyes such as methylene blue, saffronin and inuline scarlet); U.S. Pat. No. 3,761,420 (polyhydric alcohols having 2 to 6 carbons and from 2 to 6 hydroxyl groups per molecule, and a chelating agent); U.S. Pat. No. 3,781,212 (colloidal silica and/or dissolved carbon dioxide); U.S. Pat. No. 3,819,528 (calcium ion and an organic compound selected from the group consisting of aliphatic glycols and 1,3-propane diols); U.S. Pat. No. 4,111,855 (a polyacid capable of forming water-soluble calcium-complexes); U.S. Pat. No. 4,142,999 (mono- and polyvalent alcohols and ethers thereof, and an alkoxylated alkylamine); U.S. Pat. No. 4,169,817 (water soluble hydroxy alcohols selected from glycerol, alkylene glycols in which the alkylene group contains from 2 to 8 carbon atoms, such as ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, and sorbitol); U.S. Pat. No. 4,238,345 (an antioxidant and a hydrophilic polyol, which optimizes the preservative or stabilizing effect of the antioxidant); U.S. Pat. No. 4,404,115 (an alkali metal pentaborate, optionally with an alkali metal sulfite and/or a polyol): U.S. Pat. No. 4,462,922 (a mixture of boric acid or an alkali metal borate with a polyol or a polyfunctional amino compound, together with a certain level of a reducing alkali metal salt such as sodium sulfite); and U.S. Pat. No. 4,243,543 (an antioxidant and a hydrophilic polyol having a molecular weight less than about 500).
These numerous attempts to stabilize enzymes in aqueous compositions show the critical need for such compositions. None of these compositions, however, disclose the water-in-oil emulsion prespotter composition of the present invention.
Water-in-oil emulsion prespotter compositions without enzymes and polyether polyols or polyester polyols are disclosed in U.S. Pat. No. 4,438,009.
It has now been surprisingly found that enzyme degradation can be substantially avoided by formulating enzyme-containing water-in-oil emulsion prespotter laundry compositions comprising at least one of a polyester polyol having a hydroxyl number between about 28 and 690 or a polyether polyol having a hydroxyl number between about 28 and 690.
It has also been surprisingly found that enzyme-containing water-in-oil emulsion prespotter laundry compositions of this invention exhibit superior stain removal.
It is an object of this invention to provide stable enzyme-containing water-in-oil emulsion prespotter laundry compositions which retain an effective enzyme activity under prolonged storage conditions.
It is another object of this invention to provide stable enzyme-containing water-in-oil emulsion prespotter laundry compositions which exhibit excellent cleaning and stain removal properties.
These and other objects can be readily observed from the following disclosure.